The Coming Ice Age

I remember when the coming ice age was a hot topic: for science geeks, anyway.

Growing glaciers, miles deep, would spread from Earth’s arctic regions.

Grinding southward, they would obliterate cities and civilization in their inexorable advance.

It made for interesting conversation, forgettable science fiction potboilers, and at least one bit of cover art that I liked. The tale’s premise was that a city on whacking great tractor treads was trundling southward. I can’t remember the title or author.

More serious stories assumed that we didn’t survive, or had to start over in the tropics.

That was the late 1950s and early 1960s. Some folks were talking about “global cooling” in the 1970s, based on a cooling trend from the 40s to early 70s.1

Reality isn’t quite what’s in the headlines, and that’s another topic.

“Last” Glacial Maximum?

(From Hansen et al./NASA, used w/o permission.)

If someone asked if I “believe in” climate change, I’d have answer yes — and no.

I don’t “believe in” climate change in the sense that I think it explains my existence, provides a reason for living, or belongs at the top of my priorities list.

On the other hand, I think Earth’s climate is changing. I am also quite sure that the universe is billions, not thousands, of years old; Earth isn’t flat; Adam and Eve aren’t German; and thinking is not a sin. (September 23, 2016; August 28, 2016; July 22, 2016)

It’s certainly warmer now than about 26,500 years back, when glaciers covered my ancestral homelands; and most of today’s Minnesota.

We call it the Last Glacial Maximum, since it’s the most recent. But there’s no guarantee that continental ice sheets won’t come back. Given what we’re learning, it’s likely that the current interglacial period will end ‘soon,’ by geologic standards.2

Let’s put that in perspective.

Milutin Milanković: (Almost) Right

That graph shows average temperatures at Vostok Station in Antarctica — based on analysis of an oxygen isotope in deep-sea ocean sediments. It’s almost certainly not spot-on accurate: but my guess is that it’s pretty close to what actually happened.

Milutin Milanković noticed correlation between these changes and Earth’s climate in the 1920s. His theory wasn’t popular in my youth, but data collected since the ’60s shows that he was on the right track. Earth’s climate changed the way he said it did — almost.

The “100 kyr cycle” is another cyclic variation in Earth’s axis: and an issue for folks trying to make sense of Milanković cycles.

Earth’s equator is tilted 23.44 degrees from the ecliptic today. It tilts up to 24.5 degrees, and is on its way to the 22.1 degree minimum at the moment. The cycle takes about 41,000 years: hence the “41 kyr (kiloyear)” name.

So — once we know everything there is to know about Earth’s last five million years, we’ll fully understand climate change? Probably not.

Our home is much older: and hasn’t been the same since the dinosaurs died.

Climate Change After the Dinosaurs

(From Robert A. Rohde, via Wikimedia Commons, used w/o permission.)

Again, this graph comes from analysis of deep-sea sediments. It probably isn’t an exact fit with reality: but I think it’s reasonably accurate.

Continental glaciers have been spreading, melting, and spreading again ever since. Scientists figure positive and negative feedback processes have been keeping the cycle going. Exactly what those processes are is something we’re still learning.

Vastly oversimplifying the matter, we get more snow near the poles when Earth’s oceans are warmer. Sometimes the snow doesn’t entirely melt during summer. Snow and ice build up until we get glaciers scraping toward the equator.

Much of Earth’s water is tied up in glaciers by then, so sea level is lower. Between a slightly smaller ocean and colder climate, there isn’t as much snow falling: which slows down glacier production.

Somehow or other, Earth warms up and the cycle starts again. I gather that scientists still aren’t sure about what warms things up.

There’s evidence that it didn’t warm up once, more than 650,000,000 years ago.3 One of the problems scientists have with Snowball Earth is that they aren’t at all sure how Earth could have warmed up again.

It did, obviously, and I’ll get back to that.

It’s hardly surprising that we don’t fully understand ice ages.

The first inkling we had that they existed goes back to 1742, when Pierre Martel listened to what folks living in the Alps said about boulders of one sort of rock sitting on a different kind of rock.

I suspect we’re learning how much we don’t know almost as fast as we’re solving existing puzzles these days. The good news is that we’re learning: a lot, very fast.

One more graph, and I’ll get this week’s science news; and the new climate change book.

A Half-Billion Years of Climate Change

(From Dragons flight, via Wikimedia Commons, used w/o permission.)

Once again, that’s a pretty good estimate of Earth’s average temperature, based on analysis of oxygen isotopes.

We’re accustomed to a world where a mile-deep glacier covers most of Greenland, which isn’t normal for this planet.

Earth has been colder than it is today, but not by much: apart from that Snowball Earth thing I mentioned. The last I heard, scientists still aren’t sure if we’re in an interglacial period: or if the Quaternary glaciation is finally over.

One of the most sensible things I’ve read about Earth and climate change is what Oregon State University’s Christo Buizert said, discussing a polar climate cycle: “We still don’t know….” (BBC News (May 5, 2015))

1. A Cracking Ice Shelf

(From John Sonntag/NASA , via NPR, used w/o permission.)
(“A NASA scientist with project IceBridge took this photo of the crack in November.”
(NPR))

“A group of scientists is gathering today in the U.K. to discuss a slab of ice that’s cracking in Antarctica. The crack could soon split off a frozen chunk the size of Delaware….

“…The ice shelf Sevestre was studying is called Larsen C, and it now has a massive 90-mile crack running through it.

“‘The big rift is slicing the ice shelf from top to bottom,’ Sevestre says. It’s now a third of a mile deep, and as wide across as 25 highway lanes.

“But this is not just another sad climate change story. It’s more complicated….”

Folks wrote about an antarctic region long before 1820. That’s when a folks on a ship spotted the continent.

Which ship was first depends on who’s talking. It was one captained by von Bellingshausen, Imperial Russian Navy, Edward Bransfield, England’s Royal Navy; or Nathaniel Palmer, a sealer out of Stonington, Connecticut.

I’d like to think Vikings got that far, and didn’t bother to file a report with the North Sea Empire. That’s unlikely, though, and yet another topic.

My hat’s off to Rae Ellen Bichell and NPR, for this sentence: “It’s more complicated.”

I suspect that reality is, in a sense, very simple. For example, we keep finding close approximations to circles, spheres, and logarithmic spirals. Physicists keep getting closer to a working theory of everything, and that’s yet again another topic.

We’re also learning that reality is, in another sense, very complex: and interrelated.

“When we try to pick out anything by itself, we find it hitched to everything else in the universe.”
(“My First Summer in the Sierra,” John Muir (1869) via Wikiquote)

“Simply a Natural Event”

(From Jeremy Harbeck/NASA, via NPR, used w/o permission.)
(“Calving is a natural process that produces icebergs, as seen here with the Getz Ice Shelf in West Antarctica.”
(NPR))

“…’A lot of things are going on deep inside the ice,’ says Adrian Luckman, a glaciologist at Swansea University in the U.K. He’s also leading a project to track changes in the ice shelf.

“Luckman says climate change is certainly influencing this region. Larsen C used to have two neighbors to the north, Larsen A and Larsen B. As the air and water warmed, those ice shelves started melting and then splintered into shards in 1995 and 2002.

“But the crack in Larsen C seems to have happened on its own, for different reasons.

“‘This is probably not directly attributable to any warming in the region, although of course the warming won’t have helped,’ says Luckman. ‘It’s probably just simply a natural event that’s just been waiting around to happen.’…”
(Rae Ellen Bichell, NPR)

The odds are very good that at least part of this ice shelf will break off in the next few months, years, or decades. It won’t be the first time something like this happened, and almost certainly won’t be the last.

Quite a few glaciers and ice sheets eventually meet open water. As their edges get pushed out, bits and pieces crack off. The process is called ice calving. Scientists study ice calving, tourists watch it, and surfers ride the waves kicked up by falling ice.

Calving on an epic scale happened during October 1998, when a Delaware-size chunk of the Filchner-Ronne Ice Shelf broke off. It’s (remotely) possible that part or all of the West Antarctic Ice Sheet could break off.5

Snow eventually buried Halley I through IV, obliging researchers to move into newly-built quarters.

Halley V was designed to get lifted above each year’s snow accumulation, lasting until Halley VI was ready. Each of the current Halley Research Station modules stands on skis, so the station can be relocated as needed.6

The “Halloween Crack”

(From BAS, via BBC, used w/o permission.)
(“Aurora: Halley base has become a centre for the study of space weather”
(BBC News))

“…BAS is in the process of conducting such a move right now. The relocation is all but complete, with the last pod currently in the final stage of being shifted 23km to the new site.

“The move was necessitated by a chasm that had opened up in the shelf and which threatened to cut off Halley. But this huge fissure to the west of the station is not the cause of the temporary closure.

“Rather, it is another break in the ice some 17km to the north and east of the new base position. It has been dubbed the ‘Halloween Crack’ because it was discovered on 31 October….”
(Jonathan Amos, BBC News)

The British Antarctic Survey (BAS) folks don’t think part of the Brunt Ice Shelf is going to break off during the Antarctic winter.

But they can’t be sure, and don’t want folks on the ice if it does. A 19-hour power outage during the 2014 winter may have encouraged this common-sense move:

“British Antarctic Survey (BAS) is dealing with a serious operational incident at its Halley Research Station. On Wednesday 30 July 2014 a major technical issue resulted in the station losing its electrical and heating supply for 19 hours. All 13 station staff are safe and in good health….”

With nobody around to keep an eye on equipment, BAS will be deciding whether to leave some of the experiments running and hope for the best, or shut the whole thing down until winter’s end.

It’s not an easy decision, since Halley VI collects data on Earth’s atmosphere, and beyond.7

3. A New Book by Prince Charles

(From Penguin, via BBC News, used w/o permission.)
(“The cover of the book was based on an image of flooding in Uckfield, East Sussex”
(BBC News))

The hardcover book, available January 26, 2017, is already a #1 ‘meteorology’ bestseller on Amazon.com.

“Heatwaves, Floods … Disappearing Wildlife; Acid oceans”

It could be worse.

The cover illustration could show Cobb Bakers and Uckfield Pharmacy dissolving in an acid ocean as Godzilla and Hedorah battle on the skyline.

I found listings for several pharmacies in Uckfield, incidentally, but no “Uckfield Pharmacy.” I’m pretty sure both businesses are fictional.

I’m also sure that developing cleaner industrial technologies is a good idea, and that recycling makes sense.

That said, I’m not jumping on the “acid oceans” bandwagon. I’ve seen enough fizzled doomsday predictions, religious and otherwise, to be a bit cautious:

“…in ten years all important animal life in the sea will be extinct. Large areas of coastline will have to be evacuated because of the stench of dead fish….”
(Paul Ehrlich, on first Earth Day, (1970))

“…By the year 2000 the United Kingdom will be simply a small group of impoverished islands, inhabited by some 70 million hungry people….”
(Paul Ehrlich, Speech at British Institute For Biology (September 1971))

Creation and all created things are inherently good because they are of the Lord (1 Corinthians 10:26)Adapted from “Care for God’s Creation,” Our Catholic Faith in Action, United States Conference of Catholic Bishops

The responsibility that comes with our power is scary. Scary or not, though, we’ve got a job to do: taking care of the world’s resources for our reasoned use, and for future generations. (Catechism, 339, 2402, 2415)

If we’re going to do that job, we must keep studying the universe: and developing new tools using that knowledge. (Catechism, 2293–2295)

I am pretty sure that we know enough today to deliberately change Earth’s climate. I am also quite sure that we do not know enough to do so safely. Not yet.

In the short run, we should keep doing what we’re doing: reducing industrial pollution, and learning more about long-term climate changes. In the long run — that’s still another topic.

Meanwhile, being scared silly won’t help. That makes about as much sense as a shop foreman being scared of power tools.

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About Brian H. Gill

I'm a sixty-something married guy with six kids, four surviving, in a small central Minnesota town. I mostly write and make digital art. I'm only interested in three things: that which exists within the universe; that which exists beyond; and that which might exist.

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